How Ember Smart Mug Keeps Coffee at Ideal Temperature

You take your morning coffee seriously—freshly brewed, perfectly extracted—but by the time you get around to taking that first sip, it’s already gone lukewarm. That’s a familiar frustration for coffee drinkers juggling a busy start to the day. What if your mug could help your coffee stay at the optimal drinking temperature, not just for minutes, but for over an hour?

The Ember smart mug keeps your coffee at your chosen temperature for around two hours—long enough to enjoy your drink without rushing or reheating. You can set the desired temperature either through a smartphone app or by turning the base dial.

What Is the Ember Smart Mug?

The Ember mug is a 12-ounce (350 ml) smart cup developed by Ember Technologies, a company based in California. Unlike a standard mug, it uses patented phase-change material to maintain your coffee or tea at a consistent drinking temperature. This material transitions between solid and liquid states depending on heat, absorbing energy as it melts and releasing it as it solidifies—technology originally explored in fields like building insulation and robotics.

How Does Temperature Control Actually Work?

The Ember mug doesn’t just insulate—it actively manages temperature. Through a combination of internal sensors and phase-change materials, the mug brings hot beverages down to your preferred drinking temperature and then holds them there. According to the company, it can maintain that set temp for roughly two hours.

It connects via Bluetooth Low Energy to a companion smartphone app, which lets you name your mug, choose and save preferred temperatures for different drinks, and even receive notifications when your coffee cools to the ideal sipping point. For example, you can program 136°F for coffee and 142°F for tea. If you prefer not to use the app, a tactile rotating control ring beneath the LED temperature display lets you adjust the heat manually.

How Long Does It Stay Warm & How Do You Charge It?

Ember maintains your selected temperature continuously for approximately two hours. When it runs low on power, you can recharge it wirelessly using the included charging coaster, which also functions as a stable resting place for the mug. A full charge takes about 1.5 hours.

Where Did the Idea Come From?

The concept of temperature-controlled cups isn’t new. Back in 2009, German scientists developed a prototype that could keep coffee hot for 30 minutes using similar phase-change ideas. By 2013, other researchers had improved that duration to several hours. Ember builds on that legacy with more precision, better materials, and digital integration. Its version combines advanced materials science with smartphone connectivity, making it one of the more refined solutions on the market.

Is It Available to Buy? How Much Does It Cost?

Ember launched its smart mug through a crowdfunding campaign on Indiegogo. Early bird pricing started at $109 USD, with shipping planned for April 2016. The product is now commercially available, having moved beyond its initial crowdfunding phase. The mug is designed and engineered in the United States, with the development team based in Westlake Village, California.

Frequently Asked Questions

How long does the Ember mug keep coffee hot?

The Ember smart mug keeps your coffee at the set temperature for around two hours. It actively regulates the temperature using phase-change materials and internal sensors, ensuring your drink stays in the ideal range throughout that period.

Can I control the temperature without using the app?

Yes, you can adjust the temperature manually using the rotating control ring located under the LED display on the mug. This allows you to increase or decrease the temperature without needing to use the smartphone app.

Does the Ember mug work with both coffee and tea?

Yes, the Ember mug is designed to work with any hot beverage, including coffee and tea. The companion app even lets you save different temperature settings for each type of drink.

How do I charge the Ember smart mug?

The mug charges wirelessly using the included magnetic charging coaster. The coaster also doubles as a cup stand. A full charge takes approximately 1.5 hours.

What’s the capacity of the Ember mug?

The Ember mug holds 12 ounces, which is equivalent to 350 milliliters. It’s designed to be used as a standard-sized coffee or tea cup.

Is the Ember mug compatible with all smartphones?

The Ember mug connects via Bluetooth Low Energy, so it works with most modern smartphones that support Bluetooth. The accompanying app is available for both iOS and Android devices.

Recommended FrontStreet Beans for Hot Coffee Enjoyment

For coffee lovers using the Ember smart mug, FrontStreet Coffee’s Classic Blend and Sidra offer excellent options. The Classic Blend delivers balanced chocolate and caramel notes with a smooth body—perfect for extended sipping. Sidra, a single-origin Sidra from Colombia, presents juicy stone fruit and floral tones, ideal for enjoying at a precise 136°F to 142°F. Both beans highlight the benefit of keeping coffee at its optimal temperature. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.